The problem with concrete burn structures is the tendency to provide an unrealistic view of the properties of fire growth and behavior. Another aspect of concrete burn buildings and their content fires that we create is that the ceilings are not affected by the fires growth or travel.
Burn buildings or burn towers are structures that are fire resistive and constructed of concrete. They are designed specifically for repetitive use and allow for a consistent fire dynamic that is experienced by those training in them. Fires that are set in these buildings usually do not spread like they do in acquired structures. Respectively the fire simply gets larger or smaller at a specific location in a burn room within the burn building depending on the fuel load provided. Combustible class "A" materials such as pallets and straw are set up or piled up in an area within the room and then ignited. If a large fuel load of these materials is supplied you can create excessive heat conditions sometimes so intense that they can melt helmets and protective clothing. Creating some of these fires and conditions is not the reality of fighting fires nor do they provide certain realisms that firefighters are exposed to at the real deal. Because of the type of construction of burn buildings which are predominately concrete, it is relatively easy to create these intense temperatures. Normally these types of temperatures would be telling us to get out of the structure when fighting fires out in the real world.
The problem with these structures is the tendency to provide an unrealistic view of the properties of fire growth and behavior. Typically a 20- by 20-foot open room has placed in it a pile of pallets and hay and then light as firefighters are then told to go in and put the fire out. The fire is usually easily found and in a common location every time. Unlike real fires in acquired structures or actual structure fires, a search for the fire through dark smoke is usually the case. In real fires the fire spread is capable of getting larger and larger and moving from one room to another. In burn buildings, fires do not actively continue to grow and go across the ceilings or over your head as they would in a real room and contents fire. We should also remember that it is also spreading into the structure itself at real fires. As stated earlier, another problem with concrete burn rooms is that excessive temperatures can be created. Firefighters would not normally present themselves within these types of excessive temperatures. Realizing that they would be exposing themselves to possible flashover conditions they would immediately leave.
Another aspect of concrete burn buildings and their content fires that we create is that the ceilings are not affected by the fires growth or travel. In real fires as well as in acquired structures, ceiling materials burn and fall from overhead. Usually when these fires are set up in burn concrete buildings little attention is given in adding furniture and other materials found at real structure fires. In essence, instructors may not provide the creativity and realism in setting up a room within the burn building.
It is interesting to note that even in concrete burn buildings or burn towers we still have to comply with the NFPA 1403 standard. At the same time, there are ways to become creative and inventive in supplying additional realism within a burn building while still being complaint with the standards of NFPA 1403. We must also realize that within a concrete room we can provide certain types of materials and furnishings knowing that the fuel load will never affect the structure creating fire dynamics that would be unpredictable.The following are some ideas in how to get the most out of a burn room made of concrete usually found in burn buildings or burn towers which will enhance more realism in your scenarios.
The following list of materials is all encompassing. It is not meant that all of these items and materials necessarily be used at one time. More importantly they are to be used creatively together or separately to create more realism in fires established in these types of structures.
Another important note is that many of these materials require that they may be attached to walls and ceilings through the use of materials such as angle or straight iron bolted to the walls with hooks or some type of clasp systems coming off the iron strips that are attached to the walls. Which ever application is used it is imperative that you are not compromising the structure or allowing a situation to be created to cause fire extension from one room to another.
For a 20-by-20 foot room (appromaximatley):
- 1 Wood frame couch without cushions
- 1 Wooden chair
- 1 Wooden side-table or end-table
- 1 Small metal garbage can
- 1 Set of cloth drapes on a metal rod - not to exceed 48 inches
- 1 Metal or wood floor or table lamp with plastic shade removed - use cloth shade
- 10-12 Pallets - to be used as needed not all at once
- 4 Bails of hay - to be used as needed not all at once
- 1 Small carpet, thin, without rubber backing or rattan
- 2 Sheets of compressed wood chip particle board
Suggested Use of the Materials
By reviewing the above list of materials and furnishings we can see the possibilities and creative ways we can enhance the realism that a room and contents fire would produce.Let's began by looking at these items along with their use and setup.
First we have the couch. It is important that when acquiring a couch that it's framing and exterior presentation is predominantly made of wood.It is also important that all cushions are removed since they do not comply with NFPA 1403 due to their chemical makeup which produces an increase in heat and fuel load. We will replace the cushions with thin sections cutoff from the bales of hay acting as the cushions. This will obviously produce a realistic acceptable fire dynamic when it burns.
The wood frame chair may also have a cushion that needs to be removed and replaced by a cut section from the bail of hay. It is then placed in the room where you want it relative to the rest of the furnishings. The same can be said for the wooden side-table or end-table.
The small metal garbage can could be used as the ignition point of the fire by filling it with paper and hay while placing it next to the couch and its cushions made of hay. Or it can be placed in an entirely different location and used to either help start the fire or simply as a prop. This, along with a few pallets placed in a configuration into the setting with some hay, will guarantee ignition. Remember, in order to create the proper fire growth and entrainment of air, it is best to avoid setting the materials and furnishings in the middle of the room. When this arrangement is set, it allows drafting larger air entrainment into the fire causing it to free burn very quickly. You'll create a lot of flame, some heat but less smoke as well as the materials and furnishings being consumed quickly. Instead you should set up your materials and furnishings at a corner of the room but keep them off the walls. This will create steady fire growth and a good fire plume distributing flame, heat and smoke across ceiling areas along with good bank down as is found in structural fires.
The cloth drapery is another feature to add realism to any room and contents fire. In a burn building they should be hung with their metal rod over a possible metal shuttered window opening as usually found on these types of structures. The reason we do not exceed 48 inches of drapery material is because of the likelihood that the material itself may not be a hundred percent cotton and will have an additional makeup of synthetic materials in it.
The floor lamp should be predominantly made out of wood and metal providing for a known combustible type burn. Plastic lamp shades are usually removed due to their plastic makeup of hydrocarbons and heat producing fuel loads. They can easily be replaced or substituted with a makeshift lamp shade made of cloth or heavy cardboard. They can then be placed within their relative setting near the other furnishings.
The acquired pallets can be used with hay to start fires or create fires as you normally would within a concrete burn room. Here we are suggesting that they or portions of them are attached or hung on the walls near the furnishings. This will provide an increase in realism through their auto ignition from radiant and conducted heat sources from the fire. They can also be used over and over again because they would never totally burn through and would burn again once another fire is set for additional evolutions. Pallets or portions of them can also be attached to ceilings over the immediate fire area of ignition which provides additional realism in having fire travel overhead as they do in real structure fires. It is important to note when utilizing this technique that drop down from fire brands and pieces of wood should be expected and that all members should be covered with the proper protective clothing and helmets with the chin straps applied. When attaching pallets to ceilings they should be secured firmly in order to guarantee that they would never drop-down as one-piece. This is an excellent way to provide additional realism to the burn.
The particle board that is mentioned can also be used on the walls and on the ceiling. It should be cut into two-foot strips and placed in that fashion. No more than two sheets cut into the two-foot strips should be used at one time for any given fire scenario. Again adhering to NFPA 1403 the concerns regarding the particle board is not the compression of the wood chips but the glue bases that may be used in holding them together.
It is important to note that what ever types of woods are being used that they should never be chemically treated. We're looking for the most natural woods in order to provide clean and safe burning.When attaching wood products onto ceilings and walls it is important that they are only applied in the areas of origin of the fire that is being set. At no time will these products be wrapped around an entire room or near entry ways whether they are overhead or on walls.By doing so will cause an unacceptable fuel load as well as possibly producing fires behind companies and their initial entry ways.
Some of the best training and also the most realistic can be provided through the use of acquired structure. Acquired structures offer realism in a truer sense regarding fire dynamics to the training firefighter as it relates to fire suppression activities at real fires. Before we begin to train or light fires in these structures it is extremely important that the inside and outside of these buildings are properly prepared following NFPA standards and guidelines. When we light a fire in a real building we will experience real conditions. With these real conditions come the real potentials regarding fire dynamics that may pose safety risks to those training within and around the structure. Whereas in a burn building a light fire never really leaves a room, it is quite different in an acquired structure where there can be possible involvement of the structure itself as well as extension into other areas. Fire as we know in real structures along with their construction features provide for the fires ability to extend and travel into walls and ceilings. This type of training is an invaluable experience to firefighters giving them a truer perspective on what to expect at the real deal. At the same time if the preparation and the awareness of those training at these acquired structures is not conducted properly injury and death may result.
To emphasize the point again safety and control in this type of training is paramount as stated earlier along with paying attention to the guidelines provided by NFPA 1403. The following information provides for the setting up, preparation and materials needed for a room and contents fire established within NFPA guidelines while allowing for some creativity. Through the use of this type of preparation we will be able to get multiple burns out of one particular room while minimizing its extension into the structure. We can also control the fuel loads by using close to natural products as seen in class "A" materials and additionally be able to better control the growth and spreadof fire while promoting realistic conditions.
Suggested Materials and Preparations
- 2 rooms about measuring about 13 by 15 feet. Note: Any room used should be configured and prepared in a similar manner. Rooms chosen for burning will have floor joist systems below them completely intact or reinforced. All holes patched or covered. All routes for fire travel such as pipe chases and utility installations through walls and ceilings sealed off.
- The 2 rooms should be set up at one time alternating burns between both. This allows for repeated evolutions by alternating between them while allowing for cooling and drying of each room after each ignition. Rooms should be far enough apart as to not allow fire extension to ignite through radiation, convection or direct flame contact to the other room or any of its furnishings and materials.
- 8 4x8 1/2-inch drywall
- Screw gun and drywall screws
- 4 8x4 3/4-inch plywood
- 4 10-foot 2x4's
- Collected furnishings as used above in Burn Buildings.
- Pallets and Hay
- Electric powered saw for cutting plywood and other materials.
- Hammer and 16p nails
Fire Behavior and Suppression
The use and set up of the drywall is very important in regards to its placement. The drywall provides several purposes. First it covers surfaces. It also can contain heat and it can direct heat and flame within the structure away from the structural members of the building itself. This is possible only for a certain amount of time before inevitably the structural components and void spaces of the structure would become affected. Remember we are only allowing the fire to grow and burn to a certain extent and only for a certain amount of time. In other words, we are not allowing the fire to rip through the house but to control it just enough to allow it to leave the upper doorway or entrance to a room. We judge this by flame fingering that is going across a ceiling within the fire gases along with the smoke velocity approaching and arriving at the entryway to the room as well as filling the rest of the house. When the flame fingers are just emanating out of the upper portions of the doorway to the room, extinguishment must take place immediately. In order for multiple burns to take place within the same room the training instructors should monitor the use of the application of water as well as nozzle operations. The suppression company and the nozzleman should direct short bursts of water to the flame fingering and gases at the ceiling level, then sweep the floor into the room and then aim for the origin of the fire. At this point the instructors will allow the room to lift insuring that the main body of fire is out. The instructors will then indicate to the nozzleman if continued extinguishment is required in short burst. The instructor will then direct the suppression company to exit the structure with the hose line while he remains inside ventilating and checking for extension. If fire is found into the structure it will be contained and controlled by any necessary overhaul utilizing the secondary line already placed in the structure near the fire area before the exercise began. At this time any areas that need recovering can be addressed by those assisting with the live burn. After each evolution training companies should be allowed back into the structure after its ventilation to critique the training experience.
It is at this point that the same type of exercise will be conducted on the secondary room that has already been previously prepared. By alternating rooms and their burns we allow for the burning of one room to help dry out the previous burn conducted to the other room. This along with the proper control by instructors in allowing specific water applications by the training companies will maximize the ability to acquire repeated burns of the rooms in the structure. By providing proper preparation of the rooms we will ensure not loosing them to full involvement causing severe fire damage to the structure limiting the amount of burns it can provide.
Let's go back to the materials list and how we incorporate it in preparing a room for a live burn. First we will not discuss the gathering and placement of furnishings other than you can be as creative as you want when setting up a furnished room. What is important is that you follow the same guidelines as required in the information provided earlier for burn buildings or fire training towers in order to adhere to NFPA1403.
The drywall as we stated earlier has its purposes in controlling, protecting and directing flame and heat. There is a specific layout of the drywall that should be applied similarly to every room we choose to burn in.
The pallets and hay used for acquired structures should be used to initiate the fires growth. Unlike burn buildings we cannot simply pile several pallets miles high and stuff it with bails of hay. If we did the structure and its infrastructure would be affected and we could loose the building to fire as well as jeopardizing the safety of those involved. We should also never attach pallets and hay to walls or ceilings in an acquired structure for live burns. In spreading these kinds of fuel loads along combustible walls and ceilings we are creating increased surface areas which can cause rate of rise temperatures to create premature flashover conditions.
Controlling The Burn/Preventing Fire Extension
First as stated earlier we must cover all avenues of fire extension regarding unwanted holes and cut-aways through the walls and ceilings of a room. Next we need to establish the specific area in the room where the main body of ignitable combustibles will be. Remember that combustibles piled or placed in the center of a room will burn more freely and faster possibly providing a loss of control by the instructors in regards to the fires speed of growth. Whereas placing furnishings and combustibles closer to walls such as in the corner of a room will allow the entrainment of air into the fire more slowly and evenly. When we say in the corner of a room we do not mean right up against the walls but allowing for adequate space around the materials so as to be more away from the walls. This allows for better entrainment of air currents and a more evenly controlled plume of heat and fire gases up into the room to allow it to move across a ceiling towards an entryway. This is what is known as intentional fire directing and controlled fire behavior allowing for a more timed and directionally controlled event when incorporating fire suppression training. In order to do this we need to apply protection to surfaces within the room so as to prevent or delay the heat, gases and flames from attacking the infrastructure of the structure. In other words, the framing and interior spaces of walls and attics must be protected to delay their involvement. That is unless we would like fire to travel to these areas in which case this would then not be conducive to a safe and proper burn for live fire training.
Back to the placement of the drywall. Pick the corner of the room where the burn will take place. Cover this area at the ceiling, squaring in the drywall into the corners above at the ceiling and on the upper walls at the corners. The best way to attain the positioning of the drywall is to be sure to cut it into even 4x4 sections placing them like large tiles. Behind the combustibles in the corner at the base of each joining wall should be placed a 4x4 piece of drywall. Add another directly on top of those. Add an additional 4x4 to each side of those and then another to each side of those on the walls on each side. This will bring you a covering distance of approximately 12 feet of the upper wall of a room. If the room is smaller cut the last piece to fit. Depending on the height of the room will depend how high you need to continue to go up. Two 4x4 sections put one directly over the other will usually equal the height of a room with some over lap at the center seam.
The ceiling should be covered in a square made up of 4x4, pieces off the corner of the room with a single row of drywall pieces running along the sides of the ceiling where it meets the wall touching the other drywall pieces on the upper walls. Place a pair of 4x4 pieces touching the square pieces formed on the ceiling towards the direction of the doorway or entryway to the room. You are not covering the whole ceiling just the area of assumed fire travel. Do this until you reach the doorway fitting the pieces at the ceiling right up to the doorway header. Now apply one 4x4 piece of drywall to each side of the door jamb trim at the top part of the wall where it meets the ceiling. Fill in a piece above the door on the wall to the ceiling. You will also apply this to the outside area of the door jamb area on the wall at the ceiling. You will then place two 4x4 pieces of drywall on the ceiling at the wall right over the doorway. You will then cut pieces of drywall to fit and cover the entire header of the doorway inside and outside the doorway.
By preparing a room in this fashion you will be able to provide repeated burns and less chance of allowing fire into the structure. You will also provide more realism within the structure regarding fire travel, smoke conditions, smoke travel, heat currents, dropdown conditions from the drywall application during water application as well as ember dropdown and drywall dropdown. All this can be obtainable when done properly which will reduce the damage and possibilities of fire extension into the structure. Remember that proper size ventilation holes must be pre-cut above fire areas on the roof which will also allow for less damage and more productive burns.
It is recommended that during the first burn evolution you do not cover the windows if the glass and sash are present with the plywood. Allow the window to blow out in order to allow companies to deal with real fire conditions. Be sure to guarantee that no fire extension or lapping will occur during the exercise to the floor or space above. After the first evolution the window/s will need to be cover over in plywood. The plywood material should be applied and fastened in such a way that the material can be easily removed or pushed in or out from either side that it is fastened from.
None of this will work unless one of the major areas of concerns of fire behavior is addressed at live burns and that's proper ventilation. When we talk about ventilation we refer to adequate controlled ventilation for live burns in acquired structures. This is accomplished through providing the making of proper sized and properly placed ventilation holes on the roof of the structure. Ventilation holes should be placed not only at the high points on a roofs pitch but ordinarily over the fire area as well. When burning in acquired structures it is imperative that multiple ventilation holes are made. A good rule of thumb is to provide two ventilation openings of a minimum size of a 4x4 opening made on each side of a pitched roof at opposite ends. One of the openings should be closer to where the rooms of the burn areas are. Also if another pitched roof intersects another portion of a roof another ventilation hole should additionally be provided for on that portion. These tactics provide for greater control and safety from the build up and pressures from heat, smoke and hot gases giving us more control of the interior fire dynamic making it much safer.
The construction of these ventilation holes on the roof should be prepared in such a way as to be totally manipulated at will and with great ease. Cut holes 3 1 /2-by-3 1/2 at the proper locations relative to the burns and then frame them in on three sides leaving the top open. Make sure when utilizing the 2x4's for framing that the frame allows for a piece of 4x4 cut plywood to slide easily within it. Nail a make shift handle to one side of the 4x4 piece of plywood along one of its sides so you can grasp it and slide the plywood out of the framing from the other side of the ridge. Do the same for the other ventilation hole at the other location and so on. By making these ventilation holes easily manageable we can provide safety for those inside as well as those on the roof. Remember these fires should never be allowed to get to a point that they would jeopardize those training inside as well as those attending on the roof.
Related: Live Fire Training - Part 1
Lieutenant Mike Mason is a 23 year veteran of the fire service and currently assigned to Downers Grove, IL, Fire Department Engine Co. 3and heads the high rise districts and its policies for his department and all responding area departments. He is a Certified Instructor III and Fire Officer II along with being a staff instructor for the Downers Grove Fire Academy and other academies throughout the state of Illinois. He is the author of R.I.C.O., Rapid Intervention Company Operations which is recognized as the largest and most comprehensive text available on Rapid Intervention. It is respected and used by many instructors from all over the country including some organizations overseas for its content and applicability in all areas of firefighter rescue. Lt. Mason has also originated the national program entitled R.I.C.O.tm (Rapid Intervention Company Operations) which utilizes an ever changing program involving the most up to date progressive procedures, maneuvers and techniques which are taught by some of the most prominent instructors in firefighter rescue from across the nation. Lieutenant Mike Mason can be reached at firstname.lastname@example.org